1. Field of the Invention
Embodiments of the invention relate to methods and apparatus for making up and breaking out tubular connections. In particular, embodiments of the invention relate to a gripping apparatus operable to make up or break out a tubular connection.
2. Description of the Related Art
Oilfield tubulars such as drill pipe, tubing, casing, and the like are employed in sections which are joined together at their ends by threaded connections. Typically, power tong assemblies are used to make up or break out a threaded connection. A typical power tong includes a device for gripping the external surface of a tubular section and then rotating the tubular section while the tubular to which it is connected is held stationary or rotated in the opposite direction.
Existing power tong assemblies generally have one fixed gripping jaw and one active gripping jaw that are assembled in a carrier ring or inner ring. The active jaw cams onto the tubular and forces the tubular into the fixed jaw to grip and rotate the tubular. However, to change from make up to break out, or visa versa, the jaw gripping rotation must be reversed. Generally, the active jaw and fixed jaw must be manually removed and reinstalled 180 degrees in the inner ring to the rotation needed. By doing this manual jaw change the tubular must be removed from the power tong assembly and the jaws adjusted to the make or break position. This manual adjustment is time consuming and is a major safety hazard.
There are other power tong assemblies with jaw gripping designs that do not require manual adjustment of the jaws for transitioning between make up and break out. Although assemblies of this type have proven satisfactory, extensive use and experimentation has shown that improvements are needed, particularly with respect to the jaw gripping design and the means for urging the jaws into contact with the pipe.
There is a need, therefore, for a new and improved method and apparatus for making up and breaking out tubular connections. There is also a need for a new and improved jaw gripping design for engaging and disengaging a tubular during a make up or break out connection.